This invention relates to diving snorkels such as used by divers and swimmers.
Conventional diving snorkels comprise a main conduit having an upper opening for lying above the water surface during actual use of the snorkel and a lower opening lying under the water surface during actual use of the snorkel and are provided with a non-return valve adapted to be opened downwards, and a branch conduit branched from the main conduit between the upper and lower openings' which' provided at its distal end with a mouthpiece.
U.S. Pat. No. 4,834,084 discloses the snorkel in which the main conduit is radially divided in two by a baffle plate provided immediately under the mouthpiece so that a swimmer's instantaneous vigorous expiration can be rapidly guided together with a quantity of water collected within the snorkel toward the upper opening.
With conventional snorkels inclusive of the one disclosed in the above-mentioned U.S. Patent, a quantity of water flowing into the snorkel through the upper opening flows down along an inner wall of the main conduit and is collected in the proximity of the mouthpiece. While the snorkel disclosed in the U.S. Patent allows such collected water to be forced out with relatively high efficiency, it is still impossible for this snorkel to prevent more or less significant quantity of water from being collected in the proximity of the mouthpiece. Accordingly, this snorkel of prior art requires a swimmer to make frequent fatiguing purges from the proximity of the mouthpiece by his or her expiration.